Robin EH36BS User manual

CONTENTS
Section Title Page
1 . SPECIFICATIONS ....................................................................................................... 1
2 . PERFORMANCE ........................................................................................................ 3
2-1MAXIMUMOUTPUT ........................................................................................................ 3
2-2 CONTINUOUS RATED OUTPUT .................................................................................... 3
2-3 MAXIMUMTORQUE
....................................................................................................... 3
2-4 PERFORMANCECURVES
............................................................................................. 4
3 . FEATURES .................................................................................................................. 6
4 . GENERAL DESCRIPTION OF ENGINE COMPONENTS .......................................... 7
4-1 CYLINDER AND CRANKCASE ....................................................................................... 7
4-2 MAIN BEARING COVER ................................................................................................. 7
4-3 CRANKSHAFT .................................................................................................................. 7
4-4 CONNECTING ROD AND PISTON ................................................................................. 8
4-5PISTON
RINGS ............................................................................................................... 8
4-6CAMSHAFT ..................................................................................................................... 8
4-7 VALVE ARRANGEMENT ................................................................................................. 9
4-8 CYLINDER HEAD ............................................................................................................ 9
4-9GOVERNORSYSTEM .................................................................................................... 9
4-10 COOLING SYSTEM
..................................................................................................... 10
4-11LUBRICATIONSYSTEM
.............................................................................................. 10
4-12IGNITIONSYSTEM ..................................................................................................... 10
4-13 CARBURETOR
............................................................................................................. 11
4-14 AIR CLEANER
.............................................................................................................. 11
4-1
5 BALANCER ................................................................................................................... 11
4-16DECOMPRESSIONSYSTEM
..................................................................................... 12
4-17 SECTIONAL VIEW OF ENGINE
.................................................................................. 13
5 . DISASSEMBLY AND REASSEMBLY ....................................................................... 15
5-1PREPARATIONSANDSUGGESTIONS ........................................................................ 15
5-2 SPECIALTOOLS
........................................................................................................... 15
5-3 DISASSEMBLYPROCEDURES .................................................................................... 16
5-4 REASSEMBLY PROCEDURES
..................................................................................... 31
5-5 BREAK-INOPERATION ................................................................................................ 43
6. MAGNETO ................................................................................................................ 43
6-1 OPERATIONANDFUNCTION ...................................................................................... 43
6-2 BASICTHEORY ............................................................................................................ 43
6-3 WIRING DIAGRAM ........................................................................................................ 45

Section Title Page
7 . AUTOMATIC DECOMPRESSION SYSTEM ............................................................ 46
8 . CARBURETOR ........................................................................................................ 47
8-1 OPERATION AND CONSTRUCTION ............................................................................ 47
8-2 DISASSEMBLY AND REASSEMBLY ............................................................................. 48
9 . STARTING SYSTEM ................................................................................................ 50
9-1RECOILSTARTER ........................................................................................................ 50
9-2 ELECTRIC STARTER .................................................................................................... 54
10 . TROUBLESHOOTING ........................................................................................... 56
10-1STARTINGDIFFICULTIES .......................................................................................... 56
10-2 ENGINE MISFIRE ........................................................................................................ 57
10-3 ENGINE
STOPS .......................................................................................................... 57
10-4 ENGINE OVERHEAT ................................................................................................... 58
10-5 ENGINE KNOCKS
....................................................................................................... 58
10-6 ENGINE BACKFIRES THROUGH CARBURETOR ..................................................... 58
11 . INSTALLATION ..................................................................................................... 59
11-1 INSTALLING ................................................................................................................. 59
11-2 VENTILATION
.............................................................................................................. 59
11-3 EXHAUSTGAS DISCHARGE
..................................................................................... 59
11-4 POWER TRANSMISSION TO DRIVEN MACHINES
................................................... 59
12 . SERVICE DATA ....................................................................................................... 60
12-1 CLEARANCE DATAAND LIMITS ................................................................................ 60
12-2 TORQUE SPECIFICATIONS
....................................................................................... 66
12-3 OILGRADE CHART .................................................................................................... 66
13 . MAINTENANCEAND STORAGE .......................................................................... 67
13-1 DAILYMAINTENANCE ................................................................................................ 67
13-2 INITIAL 20 HRS . MAINTENANCE ............................................................................... 67
13-3 EVERY
50 HRS . (10 DAYS) MAINTENANCE ............................................................. 67
13-4 EVERY
100-200 HRS . (MONTHLY) MAINTENANCE ................................................. 68
13-5 EVERY 500-600 HRS . MAINTENANCE ...................................................................... 68
13-6 EVERY 100
HRS . (YEARLY) MAINTENANCE ............................................................ 68
13-7 ENGINE STORAGE ........................................... : ......................................................... 68

I EH36 1
MODEL ~~~ ~ ~
EH36B EH36DS EH36D EH36BS
I I I
Type Air-Cooled, 4-Cycle, Single-Cylinder,
Horizontal P.T.O. Shaft, OHV Gasoline Engine
Bore
x Stroke
8.3
Compression Ratio
404 cm3 (24.65 cu.in.)
Piston Displacement
89
x 65 mm (3.50 x 2.56 in.)
Continuous 6.3
kW (8.5 HP) /3600 r.p.m. 6.3 kW (8.5 HP) /I800 r.p.m.
output Max. 8.5 kW (1 1.5
HP) /3600 r.p.m.
8.5 kW
(1 1.5 HP) /1800 r.p.m.
~
Max. Torque 54.9
N - m (5.60 kgf - m)
/1250 r.p.m. 27.4
N - m(2.80kgfm)
/2500 r.p.m.
I
Direction of Rotation 1 CounterclockwiseAsViewedFromP.T.O. Shaft Side I
____~
Cooling system
Valve Arrangement
Forced Air Cooling
Automobile Oil SAE
#20, #30 or 1OW-30 ; Class SE or higher
Lubricant
Splash Type Lubrication
Overhead Valve
~_____
Capacity of Lubricant 1.2 liters (0.32 U.S. gal.)
Carburetor
I HorizontalDraft,FloatType
Fuel
Fuel Tank Capacity
Gravity Type
Fuel Feed System
31
0 g/kW - h (230 g/HP - h) At Continuous Rated Output Fuel Consumption Ratio
Automobile Unleaded Gasoline
7.0 liters
(1.85 U.S. gal.)
IgnitionSystem
I FlywheelMagneto(SolidState) I
Spark Plug NGK BP6ES
Charging Capacity
-
-
1/2 Camshaft Drive
Speed Reduction
Starting System
12V-1.3A
-
1 2V- 1.3A
Governor System Centrifugal Flyweight Type
Air Cleaner Double Element Type
Recoil Starter
& Recoil Stafler
& Recoil Starter
Recoil
Starter
Electric Starter
Electric Starter
Dry Weight
I 32.0 kg (70.6 Ib.) I 35.0 kg (77:2 Ib.) I 31 .O kg (68.4 Ib.) I 34.0 kg (75.0 Ib.)]
~_____
Dimensions (L x W x H)
389 mm x 431 mm x 433 mm (15.31 in. x 16.97 in. x 17.05 in.)
I
Specifications aresubject to change without notice.
- 1-

EH41 I
MODEL
EH41B EH41
DS
EH41 D EH41BS
Air-Cooled, 4-Cycle, Single-Cylinder,
Horizontal P.T.O. Shaft, OHV Gasoline Engine
I Bore x Stroke
89 x 65 mm (3.50 x 2.56 in.)
btonbisplacement 404 cm3 (24.65 cu.in.)
1
EmpressionRatio
~~
8.3 I
Continuous 7.0 kW
(9.5 HP) 13600 r.p.m.
7.0 kW
(9.5 HP) /1800 r.p.m.
Output
Max.
9.9 kW (13.5 HP) /3600 r.p.m. 9.9 kW (13.5 HP) /1800 r.p.m.
,
Max. Torque 56.8
N m (5.80kgf - m)
I
28.4 N - m(2.90kgfm)
/1250r.p.m.
/2500 r.p.m.
Direction
of Rotation
Cooling system
Counterclockwise
As Viewed From P.T.O. Shaft Side
Splash Type
Lubrication
Overhead Valve
Valve Arrangement
Forced Air Cooling
(Lubricant
I AutomobileOil SAE #20,#30or low-30 ; Class SE or higher I
Capacity of Lubricant
310 g/kW
- h (230 g/HP - h) At Continuous Rated Output
Fuel Consumption Ratio
Automobile Unleaded Gasoline
Fuel
Horizontal Draft, Float Type
Carburetor 1.2 liters (0.32
U.S. gal.)
/
7
I Fuel Feed System
T~- GravityType
1 7.0liters(1.85 US. gal.)
Ignition System
Spark Plug
Flywheel Magneto (Solid State)
12V-1.3A 12V-1.3A
-
Charging Capacity
NGK
BPGES
Starting System
Speed Reduction 1/2 Camshaft Drive
-
Governor System Centrifugal Flyweight Type
Air Cleaner Double Element Type
Electric Starter
& Recoil Starter
Recoil Starter
& Recoil Starter
Recoil Starter
Electric Starter
Dry Weight
Dimensions
(L x W x H) 389 mm x 431 mm
x 433 mm (1 5.31 in. x 16.97 in. x 17.05 in.)
~ ~~
32.0 kg (70.6 Ib.)
34.0 kg (75.0 Ib.)
31.0 kg (68.4
Ib.) 35.0 kg (77.2 Ib.)
Specifications are subject to changewithout notice. /"
- 2-

2. PERFORMANCE
2-1 MAXIMUM OUTPUT
The maximum output is the output ofanengine with its throttle valve fully opened under the condition that
all the moving parts are properly brokeninafter theinitial break-in period.
A new engine may not produce full maximum output whileitsmoving parts are still not broken-in.
NOTE :
Power curves showninthe following charts are madeinconformity with SAE internal combustion engine
standard test code
J 1349.
2-2 CONTINUOUS RATED OUTPUT
The continuous rated output is the outputof an engine at optimum governed speed whichis most favor-
able from the view pointof engine'slife and fuel consumption.
When the engine is installed on a certain equipment, it is recommendedthat the continuous output
required from the enginebe kept below this continuous rated output.
2-3 MAXIMUM TORQUE
The maximum torqueisthe torqueat the output shaft when the engine is producing maximum output at
certain revolution.
- 3-

2-4 PERFORMANCE CURVES
EH36
( ) for type B
t
kgf-m
(5.6) 2.8
(5.4) 2.7
(5.2) 2.6
!!j (5.0) 2.5
(4.8) 2.4
(4.6)
2.3
(4.4)2.2
HP
12
11
10
9
8
7
6
5
4
3
Nom
:54) 27
:52) 26
:50) 25
:48) 24
:46) 23
(44) 22
kW
9.0
8.0
7.0
6.0
5.0
4.0
3.0
2.0 24
(12) 28 (1
4)
32
(1 6)
36
(1 8)
REVOLUTION r.p.m.
- 4-

EH41
kgfom
(5.8) 2.9 1
w (5.6)2.8
-
(5.2) 2.6
I-
HP
14
13
12
11
10
9
8
7
6
5
4
3
( for tvpe B
Nom
(56) 28
(54) 27
(52) 26
kW
10.0
9.0
8.0
7.0
6.0
5.0
4.0
3.0
2.0
20 24 28 3236 x10 ’
(10) (12)(14) (16) (18)
REVOLUTION r.p.m.
- 5-

1. The overhead valve design offers a compactness,lightweight and ideal combustion characteristics
resulting in more power from lessfuel and prolonged engine life.
2. The adoptionof an inclined cylinder offers low height of engine, makingthearrangements for installing
the engine much easier for various powered equipments.
3. The vibration, free design with a balancer system and lighter reciprocating parts.
4. Combustion and mechanicalnoises have been analized acoustically and improved for bettertonal
quality and lower engine noise.
5. The automatic decompression system lightensthe recoil pull forceby 50% comparing to the conven-
tional
SV engine.
- 6-

4. GENERAL DESCRIPTION OF ENGINECOMPONENTS
4-1 CYLINDERANDCRANKCASE
The cylinder and crankcase is a single piece alu-
minum die-casting.
The cylinder liner, made of special cast iron, is
molded into the aluminum casting.
The crankcase has a mounting surface on the out-
put shaft side, where the main bearing cover is
attached.
I
Fig. 4- 1
4-2 MAIN BEARING COVER
The main bearing coverisanaluminum die-cast-
ing, whichis mountedonthe output shaft sideof
the crankcase.
Remove the main bearing coverto inspect inside
e of the engine.
Pilots and bosses are machined
on the cover for
direct mounting
of the engine onto such machines
as generators and pumps.
Oil gauges (fillers) are on both sidesof the cover
for easy maintenance.
I OilGAUGE
-
Fig. 4-2
4-3 CRANKSHAFT
The crankshaft is forged carbon steel, and the
crank pinis induction-hardened.
The output end
of the shaft has a crankshaft gear
and balancer gear thatare pressed into position.
Fig. 4-3
- 7-

4-4 CONNECTING ROD AND PISTON
The connectingrodisan aluminum alloy die-cast-
ing anditslarge and small ends function as bear-
ings.
The pistonisanaluminum alloy casting, andcar-
ries
two compression ringsand oneoilring.
4-5 PISTON RINGS
The piston ringsare made of special cast iron.
The profileof the top ringisa barrelface andthe
second ring has a tapered face.
The oil ringisdesigned for better sealing and less
Fig. 4-4
oil consumption,incombination with 3 pieces.
TOP
BARREL
@
RING
TAPER
@
RING
OIL
COMBINATION
@
RING
RING
4-6 CAMSHAFT
The camshaft for the D-typeengine is made of
special cast iron and camshaft gears arecasted
together inone piece.
Both sides
of the shaftfit intothe plane bearings
onthe crankcase and mainbearingcover.
The camshaft for B-type engineismade offorged
carbon steeland also functions as
PTO shaft.
Cam gear
is press fitted on the shaft and ball bear-
ingsare employed on the both sidesfor support-
ingthe shaft.
I
I
Fig. 4-5
Fig. 4-6
- 8-

B Theintakevalveislocated onflywheelside of the
cylinder head.
Hardalloyvalve seats are moldedinthe cylinder
head and stellite is fused to the exhaust valve face.
The cylinder baffle leads cooling air to the exhaust
valve areafor the optimum cooling.
EXHAUSTVALVEINTAKEVALVE
Fig. 4-7
4-8 CYLINDER HEAD
The cylinder head is an aluminum die-casting
which utilizes semi-spherical type combustion
chamber forthe high combustion efficiency.
Fig. 4-8
4-9 GOVERNOR SYSTEM
The governorisa centrifugal flyweight type which
ensures constant operation attheselected speed
against loadvariations.
The governor gear with governor weights is in-
stalledon the main bearing cover.
~ "
GOVERNOR GEAR
/
Fig. 4-9
- 9-

4-10 COOLING SYSTEM
The large fins on the flywheel provide sufficient
cooling air capacity for the inlet and exhaust area
and cylinder.
The cylinder baffle helps the coolingair flow effi-
ciently.
4-11 LUBRICATION SYSTEM
All the rotating and sliding parts are splash- lubri-
cated by the
oil splasheron the connecting rod.
I OIL SPLASHER
4-12 IGNITIONSYSTEM
The ignition system isatransistor controlled rnag-
net0system which consistsof a flywheel andan
ignitioncoil with a built-intransistor mounted
on
the crankcase.
This system has an automatic ignition timing ad-
vance characteristic foreasy starting.
Fig. 4- 10
FLYWHEEL I
Fig. 4- 11
P
- 10- .

4-13 CARBURETOR
The engineisequipped with a horizontal draft car-
buretor that has a float controlled fuel system and
a fixed mainjet.
The carburetors arecalibratedcarefully for sure
starting, good acceleration, less fuel consumption
andsufficient output.
For details, referto page 47, section "8 CARBU-
RETOR''.
Fig. 4-72
4-1 4 AIR CLEANER
KNOB
Air-cleaner is a heavy-dutytype with adual ele-
ment system
; the primary oneisan urethane foam
perelement.
URETHANE
(semi-wet)and secondaryone is a drytype pa-
&
FOAM
CLEANER
CASE
ELEMENT
Fig. 4- 13
4-15 BALANCER
I
Unbalanced inertia forceiscancelled by the bal-
ancer which rotates in the same speed as the
crankshaftto effectively reduce vibration.
Fig. 4-14
- 11 -

4-16 DECOMPRESSION SYSTEM
AUTOMATIC DECOMPRESSION SYSTEM
An automatic decompression mechanismwhich
opens exhaust valve before the piston reaches
compressiontop
is assembled on the camshaft
for easy starting.
RETURN SPRING
Fig. 4- 15'
- 12-

4-17 SECTIONAL VIEW OF ENGINE
MUFF
P.T.O.
MAIN BEARING COVER
Fig. 4-16
FLYWHEEL
- 13-

FUELTANKSPARKPLUG
I
BALANCER SHAFT
\
CRANKSHAFTCRANKCASE
Fig. 4-17
CAMSHAFT
- 14-

5. DISASSEMBLY AND REASSEMBLY
5-1 PREPARATIONS AND SUGGESTIONS
1) When disassembling the engine, memorizethe locations of individualparts so that they can be
reassembled correctly.
If you are uncertain of identifying someparts,it is suggestedthat tags be
attached
to them.
2) Have boxes readyto keep disassembledpartsby group.
3) To prevent losingand mispfacing, temporarily assemble each group of disassembled parts.
4) Carefully handle disassembled parts, and clean them with washingoil if necessary.
5) Usethe correct tools inthe correctway.
5-2
SPECIAL TOOLS
Tool No.
Use
Tool
209-95004-07
For pulling off the flywheel Flywheel puller with bolt
FLYWHEEL PULLER
- 15-

5-3 DISASSEMBLY PROCEDURES
fi
Step Fasteners
Remarks
and procedures
Parts to remove
Engine oildrain
(2) To discharge oil quickly, remove
(1) Remove oil drain plug and drain
1
oil.
oil gauge.
OIL LEVEL
GASKET
I
OIL DRAIN PLUG
GAUGE
Fig. 5-2
- 16-

Step Fasteners
Remarks and procedures
Parts to remove
cap
nut
2
Air cleaner cover and elements
Remove breather
pipe from cylinder
M6 flange nut :
3
2 pcs.
head.
Air cleaner base and gasket
M6 x 28 : 1 pce.
v
CAP NUT
fig. 5-3
- 17-